Auto mechanics use jacks all the time to raise cars up and down when working on them. Even individuals who work on cars out of necessity or enjoyment use jacks for lifting cars up. The easier it is to use a particular jack the better.
There are number of jacks that are on the market that vary in type and size. For example, there are the typical jacks that come with the purchase of most vehicles. It comprises a base with a lifting mechanism and a manual tool capable of inserting into the lifting mechanism and pumping the vehicle to a raised position. While this particular jack works for changing a tire along the side of a road, it does not provide an extremely stable environment.
There are also lift ramps that serve the same purpose. You drive a vehicle up on the ramps and either the front or back portion of the vehicle is lifted depending on which section is up on the ramp. This type of jack system is very common for people who work on their cars at home. It is convenient and provides a more stable environment that the typical car jack. Unfortunately, these ramps are somewhat large and cumbersome for carrying or storing.
The larger auto mechanic shops generally have a hydraulic type lift that lifts a vehicle completely off the ground. While this type of jack has its advantages when working underneath a car, should you have a need to have to start the vehicle, it becomes problematic. However, if you are changing the brakes or rotating the tires, this is an ideal situation because you have all four wheels off the ground at one time and do not have to worry about moving the jack from one place to another or having to have more than one jack. Some of the smaller mechanic shops or individual mechanics have what is called a floor jack. This is a jack that is capable of being rolled around on the floor from one spot to another based on what portion of the car you need to have lifted. This type of jack also works well when you are removing certain parts of a vehicle, i.e. the transmission. Because the transmission come out from under the car, this type of jack can be placed under the transmission so that when it is unbolted, the transmission rests on the jack and can then be wheeled out from under the car. Generally, these types of jacks work to lift with a pumping method. However, some of them do work off of an air compressor.
There are also a number of other hand jacks available on the market. An individuals needs would be the determining factor in selecting a jack.
One example of a hand jack is disclosed in U.S. Pat. No. 4,289,300 by Weisser et al. This particular jack comprises a column attached at its bottom to a base, and a load carrying arm pivoted to the column and moveable by a screw spindle. By turning the screw spindle in one direction the jack serves to lift, by turning the opposite direction, the jack serves to lower. Portions of this particular configuration has been incorporated into a number of jacks. The screw spindle has even been used in smaller versions of floor jacks.
Another version of a car jack is disclosed in U.S. Pat. Nos. 5,118,083 and 5,197,714 by Metzen. In this particular configuration, an upright member is provided with a pivotable base plate hinged on a first pivot at the bottom of the upright member. The base plate is held into place by a spring which has two sections. A first section of the spring rests against the upright and the base plate, whereas the second section of the spring rests against he base plate and an end of the supporting arm when the arm is completely folded up and against the upright.
There are lots of jacks available from hand operated jacks to much more sophisticated jacks. The driving factor behind using a particular jack is the ease of use and the environment in which the jack is being used, as well as the particular need for which the jack is being used.